The present invention comprises a new and distinct cultivar of hybrid Prunus known by the varietal name ‘Piku 4’. The new variety was discovered in 1976 in a selective breeding program designed to produce growth reducing rootstock for cherry trees in Dresden-Pillnitz, Germany as a cross between an unnamed, unpatented variety of Prunus cerasus (Schattenmorelle) (female parent) and an unnamed, unpatented variety of Prunus “Kursar” (P. kurilensis×P. sargentii) (male parent). The new variety differs from its parents in its growth habit. The following characteristic distinguish the new variety from Prunus avium rootstock varieties:                1. Three-way hybrid.        2. Reduces growth in grafted varieties by 30-40%.        3. Suitable for sandy soil.        4. Precocious crop.        5. Glossiness of upper leaf surface.        6. Growth habit.        
The new variety was first asexually reproduced via green cuttings in 1980 in Dresden-Pillnitz, Germany and subsequent propagation therein has confirmed that the characteristics of the new variety are stable and are transmitted to subsequent generations.